MuscleNerd erinnerte kürzlich via Twitter an seine kurze , wie man den DFU-Modus auch ohne Tasten erreichen kann:

Die Datei-Endung der gewünschten ipsw-Datei von .ipsw auf .zip ändern, mit Winzip oder WinRAR öffnen, die Datei applelogo.**.img3 kopieren und im Unterverzeichnis „Firmware/all_flash“ die Datei LLB.m.**RELEASE.img3 damit überschreiben (** ist eine zweistellige Zahl, je nach Modell).

DFU-Modus ohne Tasten erreichen

Alle Details:

How to do it:

1. Create a copy of the original apple firmware and change the file extension from .ipsw to .zip

2. Unpack the .zip file to view its content. Navigate to Firmware > all_flash

3. Inside you will get two folders ( all_flash.m68ap.production and all_flash.n82ap.production ) and both of them will contain various files. The ones you are interested in are:
LLB.m ** ap.RELEASE.img3
applelogo.xxx.img3
NOTE: asterisks stands for 68 or 82 – depending on the folder. “xxx” is a different number for each device.

4. Delete the LLB.m ** ap.RELEASE.img3 file in both folders and rename the applelogo.xxx.img3 file to LLB.m ** ap.RELEASE.img3

5. Save everything and rename the file back from .zip to .ipsw

6. Connect your iPhone or iPod Touch to your computer, open iTunes and click the “Restore” button while holding down the Alt key if you're using Mac (Shift key if you're on Windows).Now browsed for the modified .ipsw and restore your device with it.When iTunes is done restoring your device with the custom firmware, your iPhone/iTouch will load directly into the DFU mode and now you can restore with a custom jailbreak firmware.

So basically what you are doing here is, making LLB (which is not there) invalidate iBoot which causes it to go into a DFU loop. (thx iH8sn0w for your input )

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